The sole cause of flaccid paralysis in the food poisoning disease known as botulism is a neurotoxin (NT) of approximately 150 kDa, which is produced as antigenically distinct serotypes (types A, B, C, D, E, F and G) by certain strains of Clostridium botulinum, C. butyricum, and C. barrati. In contaminated food, as well as in bacterial culture, the NT is noncovalently associated with non-neurotoxic proteins (non-NTs) in a large, up to 900 kDa, and stable complex. These non-NTs may and may not have hemagglutinating activity and are often immunologically related. For example, type A non-NTs have potent hemaglutinating activity and the non-NTs from type A and B complexes are serologically cross-reactive.
Botulinum toxin complexes, primarily a mixture of types A and B, are also used in biological weapons. Because of the harmful effect such weapons could have on the health of military personnel and civilian populations, as well as the potential for contracting food poisoning from botulinum-contaminated food, there is a need for quick and inexpensive detection of the presence of botulinum toxin type A and/or B in air, water, and food samples.